Butyl ricinoleate

Endpoint summary

Description of key information

Not sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

predates REACH preference for LLNA

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

18 March 1999-19 April 1999

Reliability:

1 (reliable without restriction)

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The LLNA guideline study was not validated at the time the ginea pig was performed (1999) Predates REACH recommendation for LLNA and Commission Regulation (EU) 2016/1688

Species:

guinea pig

Sex:

male/female

Details on test animals and environmental conditions:

Animals
Species and strain: Dunkin-Hartley guinea-pigs.
Reason for this choice: species generally accepted by regulatory authorities for this type of study. The strain used bas been shown to produce a satisfactory sensitization response using known positive sensitizers.
Breeder: Charles River France, 76410 Saint-Aubin-lès-Elbeuf, France. Number: . one male and one female for the preliminary test,
. 30 animais (15 males and 15 females) for the main test.
Females were nulliparous and non-pregnant.
Allocation of the animais to the groups: on day -1, the animais were weighed and randomly allocated to two groups: a control group 1 consisting of ten animais (five males and five females) and a treated group 2 consisting of 20 animais (ten males and ten females).
Weight: on day 1, the animais of the main test were approximately 3 months old and had a mean body weight ± standard deviation of 382 ± 14 g for the males and 357 ± IO g for the females.
Acclimatization: at Ieast 5 days before the beginning of the study. Identification of the animais: ear-tattoo.

Environmental conditions
The conditions in the animal room were set as follows:
. temperature: 21 ± 2°C
.relative humidity: 30 to 70%
. light/dark cycle: 12 h/12 h
. ventilation: approximately 12 cycles/heur of filtered, non-recycled air.
The temperature and relative humidity were under continuous control and recording. The records were checked daily and filed. In addition to these daily checks, the housing conditions and corresponding instrumentation and equipment are verified and calibrated at regular intervals.
During the acclimatization period and throughout the study, the animais were housed individually in polycarbonate cages (48 cm x 27 cm x 20 cm) equipped with a polypropylene bottle.
Dust-free sawdust was provided as litter (SICSA, 92142 Alfortville, France).
Bacteriological and chemical analyses of the sawdust, including the detection of possible contaminants (pesticides, heavy metals), are performed regularly by externat laboratories.
The results of these analyses are archived at CIT.

Food and water
During the study, the animals had free access to "106 pelleted diet" (UAR, 91360 Villemoisson­ sur-Orge, France).
Food is analysed regularly by the supplier for composition and contaminant levels. The diet formula is presented in appendix 2.

Drinking water filtered by a FG Millipore membrane (0.22 micron) was provided ad libitum. Bacteriological and chemical analyses of the water and diet, including the detection of possible contaminants (pesticides, heavy metals and nitrosamines), are performed regularly by extemal laboratories.
The results of these analyses are archived at CIT.

No contaminants were known to have been present in the diet, drinking water or bedding material at levels which may be expected to have interfered with or prejudiced the outcome of the study.

Route:

intradermal

Vehicle:

corn oil

Concentration / amount:

25%

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

0,5ml

Day(s)/duration:

24h

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

0,5 ml

Day(s)/duration:

24 hours

Adequacy of challenge:

not specified

No. of animals per dose:

5 males and 5 females (controls), 10 males and 10 females (treated)

Details on study design:

Thirty guinea-pigs were allocated to two groups: a control group 1 (five males and five females) and a treated group 2 (ten males and ten females).

On day l, intradermal injections of Freund's complete adjuvant mixed with the test substance (treated group) or the vehicle (control group) were performed in the interscapular region.

On day 7, the same region received a topical application of sodium lauryl sulfate in vaseline (10%, w/w) in order to induce local irritation.

On day 8, the test substance (treated group) or the vehicle (control group) was applied to the same test site which was then covered by an occlusive dressing for 48 hours.

On day 22, after a rest period of 12 days, ail animais of the treated and control groups were challenged by a cutaneous application of the test substance to the right flank. The left flank served as control and received the vehicle only. Test substance and vehicle were maintained under an occlusive dressing for 24 hours.
Skin reactions were evaluated approximately 24 and 48 hours after removal of the dressing. Test substance concentrations were as follows:
Induction (treated group)
intradermal injections: RICINOLEATE DE METHYLE at the concentration of 25% (w/w) in corn oil,
. topical application: RICINOLEATE DE METHYLE undiluted.

Challenge (all groups)
. topical application: RICINOLEATE DE METHYLE undiluted.


At the end of the study, animais were killed without examination of internai organs. No skin samples were taken from the challenge application sites.

The sensitivity of the guinea-pigs in CIT experimental conditions was checked with a positive sensitizer, 2,4-Dinitro Chlorobenzene (DNCB). During the induction period, the reference substance DNCB was applied at the concentrations of 0.1% (w/w) (day 1) and 1% (w/w) (day 8) in corn oil. For the challenge application, the reference substance DNCB was applied at the concentration of 1% (w/w) in corn oil.

Challenge controls:

Challenge (all groups)
. topical application: RICINOLEATE DE METHYLE undiluted.

Positive control substance(s):

yes

Positive control results:

The species and strain which were used showed a satisfactory sensitization response in 90% animais treated with DNCB.

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

very slight erythema observed in 1/10 controls and 5/20 treated animals

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

no indication of skin sensitisation

 Clinicat examinations

No clinicat signs and no mortality were observed during the study.

 

The body weight gain of the treated animals was normal when compared to that of the control animals (figures 2 and 3, appendix 3).

 

Scoring of cutaneous reactions

 End of the induction period

On day10, after the cutaneous application of the induction period, signs of irritation  were observed at the interscapular test site in the control and treated groups.

Scoring of skin reactions was as follows:

 

Sex          Animal

Controlgroup

----------24-h-ou-r-s--------------------48-h-ou-r-s----------

LF RF LF RF LF RF LF RF Male 31 0 0 0 0 O/S O/S 0 0   32 0 0 0 0 0 0 0 0   33 0 0 0 0 0 0 0 0   34 0 0 0 0 0 O/S 0 0   35 0 0 0 0 O/S O/S 0 0 Female 46 0 0 0 0 0 O/S 0 0   47 0 0 0 0 0 0 0 0   48 0 0 0 0 0 O/S 0 0   49 0 0 0 0 0 0 0 0   50 0   0 0 0 O/S 0 0 Treatedgroup

number               Erythema                         Oedema                         Erythema                         Oedema

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sex          Animal

-----------24-h-ou-r-s--------------------48-h-ou-r-s----------

number               Erythema                         Oedema                         Erythema                         Oedema

 

		LF	RF	LF	RF	LF	RF	LF	RF
Male	36	0	1	0	0	0	O/S	0	0
	37	0	0	0	0	0	O/S	0	0
	38	0	0	0	0	0	O/S	0	0
	39	0	0	0	0	0	0	0	0
	40	0	0	0	0	0	0	0	0
	41	0		0	0	0	O/S	0	0
	42	0	l	0	0	0	O/S	0	0
	43	0	0	0	0	0	0	0	0
	44	0	0	0	0	O/S	O/S	0	0
	45	0	0	0	0	0	0	0	0
Female	51	0	0	0	0	0	O/S	0	0
	52	0	l	0	0	0	O/S	0	0
	53	0	0	0	0	0	0	0	0
	54	0	0	0	0	0	0	0	0
	55	0	0	0	0	0	0	0	0
	56	0	0	0	0	0	0	0	0
	57	0	0	0	0	O/S	0	0	0
	58	0	0	0	0	0	0	0	0
	59	0	l	0	0	O/S	O/S	0	0
	60	0	0	0	0	0	O/S	0	0

LF: leftflank (vehicle)

RF:right flank (undiluted test substance)

s : dryness of the skin

Interpretation of results:

GHS criteria not met

Conclusions:

Methyl Ricinoleate is not a skin sensitizer according to the OECD 406 guideline study.

Executive summary:

The sensitization potential of the test substance RICINOLEATE DE METHYLE was evaluated in the Guinea-pig according to the maximization procedure by Magnusson and Kligman. 20 Dunkin-Hartley guinea pigs (10 males and 10 females) were treated in the test group. The test substance was applied by intradermal injection at a concentration of 25% in corn oil, after 9 days, the animals were induced (and irritation by sodium lauryl sulfate in vaseline) epicutanously by the undiluted test item. On day 22, after a rest period of 12days,treated animals and controls were challenged by a cutaneous application of the test substance to the right flank The left flank served as control and received the vehicle  only . Test substance and vehicle were maintained under an occlusive dressing for 24hours.

Skin reactions were evaluated approximately 24 and 48 hours after removal of the dressing.

No symptoms, mortality or cutaneaous reactions due to any sensitization process by treatment with the test substance, RICINOLETATE DE METHYLE , were observed in guinea pigs.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Valid data exist on dermal sensitisation of a structural analogue, methyl ricinoleate. The substance is clearly a nonsensitiser in a Buehler assay (OECD 406). Further evidence of a lack of sensitisation are provided from experimental and clinical studies on other analogues in a category of castor oil compounds, including esters (Johnson, 2007). Read-across is substantiated for the target substance and it is not classified for sensitisation.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Sensitisation data on the analogue substance, and therefore the target substance, are found to be adequate and do not meet the criteria for classification, according to Regulation EC No. 1272/2008.